Narrator (April Hobart, CXC): For many years, astronomers have known about two distinct classes of black holes. The first is called stellar-mass black holes, containing between five and thirty times the mass of our Sun. The second well-known category of black is known as supermassive black holes. These black holes are giants found at the centers of galaxies, weighing millions or even billions of times the Sun's mass. What about black holes that fall in between? Astronomers have been trying to find and study these intermediate-mass black holes for many years. A newly discovered object in the galaxy NGC 2276 may be an important step in that direction. By combining X-rays from Chandra along with radio data, scientists determined that this object in one of the galaxy's spiral arms is about 50,000 times the mass of the Sun - a perfect fit for an intermediate-mass black hole. Astronomers also used these data to look at what kind of impact this source may be having on its surroundings. They found that this intermediate-mass black hole is producing a jet that appears to be squelching the formation of stars around it. Scientists will continue to study this and other intermediate-mass black holes to see how they fit into the larger picture of black holes, galaxies, and the Universe.